JPS63112332A - Automatic paper feeder - Google Patents

Abstract

PURPOSE:To simplify structure and operation, by making the paper conveying speed made by a paper conveying device faster than peripheral velocity of a separate roller, and performing driving force transmission from a paper feeding drive shaft to the separate roller via a transmission delay mechanism part, in case of a printer or the like. CONSTITUTION:When the insertion of paper is detected by a sensor 310 and a main feed roller 37 is rotated, a pin 36a pushes a pin 36b whereby a separate roller 31 and an elastic member 33 both are rotated. With this rotation, the elastic member 33 strips off the topmost paper, feeding it into the separate roller 31. The paper from the second sheet downward is stopped its movement by a separate plate 34. When a sensor 311 detects a tip of the paper, travel speed of the paper and peripheral velocity of the separate roller 31 both come to be equal to peripheral velocity of the roller 37, but each revolving speed of a paper feeding drive shaft 32 and a roller 35 is not varied at all. With this peripheral velocity difference, an angle of delay theta is produced between these pins 36a and 36b of a transmission delay mechanism part. For a while till this angle of delay theta comes to zero, the roller 37 only rotates, continuing to feed the first paper. When this angle of delay theta comes to zero, the second paper is delivered.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an automatic paper feeder used in facsimiles, printers, and the like.

BACKGROUND OF THE INVENTION In recent years, automatic paper feeding has become an essential function for facsimile machines and the like as a labor-saving function to cope with the increase in communication volume due to faster speeds, and has been incorporated into most medium-speed and high-speed machines. Automatic paper feeding in a facsimile machine is required to be highly reliable, such as being able to handle a wide variety of transmitted documents and paper quality, and preventing missing received images due to double-sheet feeding. For automatic paper feeding,
There are methods that utilize differences in frictional force and methods that utilize separation by vacuum suction, but due to cost and size constraints,
A frictional separation method with the addition of a suitable auxiliary feed mechanism is generally employed.

A conventional automatic paper feeder will be described below.

5, 6, and 7 are a plan view, a cross-sectional view, and a side view of a main part of an automatic paper feeder used in a conventional facsimile machine, respectively.

In the figure, reference numeral 21 denotes a separation roller that separates sheets of paper one by one, and is attached to a rotating shaft via a one-way clutch. 22 is a separation plate, 23 is an eccentric roller that performs auxiliary feeding of the paper, 24 is a main feed roller that main feeds the paper, and 25 is a separation roller 2 from the drive system of the main feed roller 24.
1 and a solenoid that separates the drive of the eccentric roller 23;
6 is a paper feed system drive motor, 27 is a spring that urges the separation plate 22 to the separation roller 21, 28 is a semicircular roller that presses the paper,
29 is a leaf spring that biases the semicircular roller 28; 210 is a sensor that detects the insertion of paper; 211 is an eccentric roller positioning sensor; 212 is a sensor that confirms the leading and trailing ends of the paper; a is the paper insertion direction; and b is Indicates the paper ejection direction, P1~
P4 is a drive pulley, G1-G5 are drive gears, 213 is a lever that separates gear G1 and gear G2 by the operation of solenoid 25, 214 is a return spring for solenoid 25, 2
15 is an actuator of the solenoid 25, 216 is a driving timing belt, 217 is a separation roller shaft, 218 is an eccentric roller shaft, and 219 is a main feed roller shaft.

The operation of the automatic paper feeder configured as described above will be explained below in order.

The sensor 210 detects that paper is inserted, and the solenoid 25 is energized.
The lever 213 is rotated around the axis of the gear G3, the gear G2 and the gear G1 are engaged, and the drive of the main feed roller 24 is transmitted to the separation roller 21 and the eccentric roller 23. As a result, the eccentric roller 23
The bottom paper is sent toward the separation roller 21 and the separation plate 22. Here, the papers other than the bottom paper are stopped by the separation plate, and only the bottom paper is sent to the main feed roller 24.

Next, the sensor 212 detects the leading edge of the fed paper, and the sensor 211 positions the eccentric roller 23 at the position indicated by the dotted line in FIG. 25 actuators 21
5 and rotate the lever 213 to return it to the position shown by the dotted line in FIG. 7, thereby disengaging the gears G2 and G1. As a result, the rotation of the separation roller 21 and the eccentric roller 23 is stopped, and the feeding of the first sheet is continued using only the main feeding roller 24. During this time, the second sheet of paper that will be fed next is not fed, so between the first and second sheet,
You can set page spacing.

Next, the sensor 212 detects the end of the first sheet of paper, and the solenoid 25 is energized again, so that the lever 213
The gears G2 and G1 are engaged with each other through the gears G2 and G1, and the driving force is transmitted to the separation roller 21 and the eccentric roller 23, and the second sheet of paper is fed by the same operation as described above. By repeating these series of operations, automatic paper feeding is performed.

However, what are the problems that the invention attempts to solve with the above conventional configuration? + [i] Since an eccentric roller or a semicircular roller is used for the auxiliary feed mechanism, and a solenoid or gear switching lever is used to maintain the page spacing, the machine 414 and its operation are complicated, and there are many parts, resulting in a high price. In addition, since the device requires a large space for arranging its parts, the device becomes large in size, and it is also difficult to assemble.

Means for Solving the Problems The present invention provides a paper conveyance means that further conveys the paper fed by the separation roller and the separation member by rotation of the separation roller, and separates the paper conveyance speed by this paper conveyance means. It was configured such that the driving force was transmitted from the paper feed drive shaft to the separation roller via a transmission delay mechanism.

Operation According to the present invention, the paper separation mechanism can be entirely disposed on the paper feed drive shaft with the above configuration.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows an external perspective view of the vicinity of a paper feed drive shaft of an automatic paper feeder in an embodiment of the present invention.

In FIG. 1, 31 is a separation roller rotatably attached to the paper feed drive shaft 32, and 33 is a rubber elastic member, which is attached to the separation roller 31 and rotates at the same time as the separation roller. 34 is a separation plate for separating the sheets. 35 is a roller that is locked and driven when the paper feed drive shaft rotates in the direction of arrow A, but is free to rotate in the opposite direction.

Reference numerals 36a and 36b are bins (engagement #) provided upright on the end faces of the roller 35 and the separation roller 31, respectively, and the roller 35 and the bins 36a and 36b constitute a transmission delay mechanism section 40.

FIGS. 2 and 3 are a plan view and a side view of the main parts of an automatic paper feeder according to an embodiment of the present invention.

In the figure, 37 is a main feed roller, 38 is a main feed roller shaft, and 39 is a contact type image sensor that reads the image written on the paper on the main feed roller 37, and is urged by the main feed roller 37. The main feed roller 37 and the three contact type image sensors constitute a sheet conveyance means, and the rotation of the separation roller further conveys the sheet fed by the separation roller 31 and the separation plate 34.

310 is a sensor for detecting the insertion of paper, 311 is a sensor for detecting the leading and trailing ends of the fed paper, 312 is a switch for positioning the elastic member, gl, g2. g3 is the main feed roller drive gear, g4゜g5. g6 is a gear that drives the separation roller 31, 313 is a driving step motor,
Arrow a is the paper insertion direction, and arrow s is the paper ejection direction.

FIG. 4 is a side view of essential parts for explaining the flow of operation of the automatic paper feeder in one embodiment of the present invention.

The operation of the automatic paper feeder configured as described above will be explained step by step based on FIGS. 3 and 4.

First, as shown in FIG. 4(a), the elastic member 33 is stopped at the ON position of the switch 312 and held in a paper insertion standby state. When the insertion of paper is detected by the sensor 310, the drive step motor rotates, and when the main feed roller 37 rotates, the bin 36a pushes the bin 36b, causing the separation roller 31 and the elastic member 33 to rotate. As a result, as shown in FIG. 4(b), the elastic member 33 strips off the top sheet of the inserted sheets and sends it to the separation roller 31. At this time, paper other than paper on the - grade is placed on the separation plate 3.
4 will stop the movement. When the first sheet of paper is further fed, the elastic member 33 bends as shown in FIG. 4(c) and continues to feed the sheet, until the leading edge of the sheet is detected by the sensor 311 at the position shown in FIG. 4(d). Detect. Further, the first sheet of paper is advanced by a certain amount and sent to the main feed roller 37 as shown in FIG. 4(e). From here, the moving speed of the paper and the circumferential speed of the separation roller 31 become equal to the circumferential speed of the main feed roller 37, but the rotational speeds of the paper feed drive shaft 32 and the roller 35 do not change, so the state shown in FIG. 4(f) occurs. That is, until the end of the first sheet leaves the separation roller 31, a delay angle θ is generated between the bins 36a and 36b of the transmission delay mechanism 40 due to the difference in circumferential speed. From the state shown in Fig. 4(f) until this delay angle becomes "O" (state shown in Fig. 4(g))
, the separation roller 31 and the elastic member 33 do not rotate, and only the main feed roller 37 rotates to continue feeding the first sheet of paper, so that a sufficient page interval can be maintained between the first and second sheets. . Furthermore, when the first sheet of paper is continued to be fed, the delay angle is rQ, so the elastic member 33 is moved to the second sheet of paper (at this point, this second sheet of paper comes to the top). is stripped off and sent to the separation roller 31. On the other hand, the first sheet of paper is also sent by the main feed roller 37, and the sensor 31
1 to detect the end. Automatic paper feeding is performed by repeating the operations from step 1 to step 8 above.

Although rubber is used as the elastic member in the present invention, it is also possible to use a plate spring or a combination of a coil spring and a friction member.

Effects of the Invention As described above, in the present invention, an elastic body is attached to a separation roller in a state protruding from its outer periphery, and the paper fed by the separation roller and the separation plate is further conveyed by rotation of the separation roller. A paper conveyance means is provided, and the paper conveyance speed of the paper conveyance means is faster than the circumferential speed of the separation roller, and the driving force is transmitted from the paper feed drive shaft to the separation roller via a transmission delay mechanism section. By this,
The mechanism and operation are simplified, and the number of parts is small.
It is easy to assemble (and saves space), making it possible to create an inexpensive automatic paper feeder.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of the vicinity of the paper feed drive shaft of an automatic paper feeder in an embodiment of the present invention, FIG. 2 is a plan view of the main parts of the automatic paper feeder in the same embodiment, and FIG. The figure is a side view of the main parts of the automatic paper feeder in the same embodiment, FIG. 5 is a plan view of essential parts of a conventional automatic paper feeder, FIG. 6 is a sectional view taken along line AA in FIG. 5, and FIG. 7 is a side view of the same. 31...Separation roller, 32...Paper feed drive shaft, 33...Elastic member, 34...Separation plate, 35...Roller , 36a, 36b...Bin (engaging portion), 40...
...Transmission Delay Mechanism Department, Name of Agent: Patent Attorney Toshio Nakao and 1 other person

Claims (1)

[Claims] (1) A drive motor, a paper feed drive shaft that is rotated by the drive motor, and a part of the paper feed drive shaft that is attached to the paper feed drive shaft and that rotates in accordance with the rotation of the paper feed drive shaft in only one direction. a roller that is rotatably attached to the paper feed drive shaft and has a first engaging portion at a portion of the roller; a separation roller having a second engaging portion that is pushed and driven; a separation member disposed opposite to the separation roller that sandwiches the paper between the separation roller and conveys the paper at a first speed; a paper conveyance means for conveying the paper at a second speed faster than the first speed, and when the separation roller rotates at an angular velocity exceeding the rotational angular velocity of the roller, the first and second engaging portions An automatic paper feeder configured so that the engagement of the two is disengaged.